According to the quality analysis requirement by GB/T 1419—2004 Sponge Platinum, GB/T 15000—2003 Directives for the Work of Reference Materials, and YS/T 409—1998 Specification for Certified Reference Materials for Non-ferrous Product Analysis, with 99.999 % high purity platinum as matrix, solution addition method is used to prepare the reference sample for spectral analysis of platinum. The experiment includes preparation of impurity reference solution, chemical composition design of reference sample and preparation flowsheet. Besides, the homogeneity test, stability test, value determination, and working curve drawing are carried out. The analysis and test results show that the reference sample for spectral analysis of platinum has good homogeneity and stability, the working curve has even gradient, the linear relation is good and each technical index meets the spectral quantification analysis requirement by GB/T 1419—2004 Sponge Platinum（w（Pt）=99.9 %-99.99 %）.